February 02, 2016
(8.1) Geometric Mean
Objective: To find the geometric mean of 2 numbers.
To use geometric mean in similar triangles to find
lengths.
Why: Geometric mean can be used to find lengths we were not
able to find before.
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
8.1 Similar Right Triangles
To use geometric mean in similar triangles to find lengths.
With a 3 x 5 card, use a straightedge to form 3 right
triangles as seen below. Cut the three triangles out.
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
C
A
To use geometric mean in similar triangles to find lengths.
B
D
ADC ~
(1 & 2)
AD
AC =
ACB ~
CDB
(1 & 3)
AD
=
CD
(2 & 3)
AB
CB =
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
To use geometric mean in similar triangles to find lengths.
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
1.
To use geometric mean in similar triangles to find lengths.
x
6
10
February 02, 2016
2.
5
y
Obj: To find the geometric mean of 2 numbers.
To use geometric mean in similar triangles to find lengths.
8
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
3.
To use geometric mean in similar triangles to find lengths.
h
16
5.75
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
4.
y
4
z
x
9
To use geometric mean in similar triangles to find lengths.
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
5.
x
9
15
To use geometric mean in similar triangles to find lengths.
y
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
6.
25
To use geometric mean in similar triangles to find lengths.
9
w
z
y
x
February 02, 2016
Obj: To find the geometric mean of 2 numbers.
To use geometric mean in similar triangles to find lengths.
HF:
(HR): (8.1) Pg.541: 15, 18, 19, 21, 27, 29, 34-36, 50